1. Field of the Invention
The invention relates generally to emergency lighting fixtures including illuminated signs and emergency lighting units and particularly relates to combinations of illuminated exit signs and the like with emergency lighting units to form fixtures having multiple emergency lighting functions in a single device.
2. Background of the Invention
Emergency lighting capability is mandated by building codes throughout most of the world for commercial buildings in particular. The most common type of emergency lighting is the exit sign which is also the most noticed due not only to its ubiquity but also due to the fact that most exit signs are constantly illuminated and are therefore readily seen. Exit signs are typically placed above doorways or in egress paths to indicate in a time of emergency the most efficient manner of exiting a building. Another common form of emergency lighting is generally referred to as an emergency lighting unit and typically operates two spaced lamps which are often referred to as xe2x80x9cfrog eyesxe2x80x9d. Emergency lighting units operate only in the event of emergency and are intended to supply an acceptable degree of ambient illumination under emergency conditions, these conditions usually including loss of normal power. Since emergency conditions requiring the most immediate and effective use of both exit signs and emergency lighting units are normally associated with mains power loss, backup power is necessary for the continued operation of an exit sign and for start-up and continuing operation of an emergency lighting unit. This back-up power is provided by batteries, a typical exit sign having a battery and circuitry capable of switching to DC battery power from AC mains power on loss of AC power to the exit sign. An emergency lighting unit includes a battery and sensing circuitry which initiates operation of the battery on loss of normal building power, the lamps of the emergency lighting unit being then activated to provide emergency lighting. These two forms of emergency lighting, the exit sign and the emergency lighting unit, are placed in a building structure at locations requiring a particular function of each form. Certain situations require the use of both forms of emergency lighting in one location. Rather than USQ separate lighting fixtures in one particular location, common practice has been to use a xe2x80x9ccombinationxe2x80x9d exit sign and emergency lighting unit, this type of fixture being commonly referred to as an exit/unit combo. The xe2x80x9ccomboxe2x80x9d has previously taken the form of an emergency lighting unit mounted to an exit sign, the emergency lighting unit most often being mounted along the top of the exit sign. In most instances, the exit sign and the emergency unit operate separately although certain functions can be shared between the exit sign and the unit by providing common circuitry such as would be useful to detect power line failure for switching the exit sign to DC battery power and for initiating operation of the emergency lighting unit. A particular exit/unit combo which has enjoyed substantial market acceptance is the QUANTUM Exit/Unit Combo manufactured by Lithonia Lighting, Inc. of Conyers, Ga., a wholly owned subsidiary of National Service Industries, Inc., of Atlanta, Ga., QUANTUM being a trademark of National Service Industries, Inc. The widespread use of the Lithonia Lighting combo has been brought about at least in part due to the reduced labor costs associated with installation of the Lithonia combo on site, the exit sign and the emergency lighting unit being factory assembled and prewired for shipment to a job site in a configuration allowing rapid and simultaneous final wiring of both the exit sign and the emergency lighting unit. Further, the Lithonia combo manufactured and marketed under the QUANTUM mark is comprised of a substantially all-plastic exit sign and a substantially all-plastic emergency lighting unit, thereby resulting in a combo product which is light in weight relative to previous combo products many of which included metal housings and parts which caused the products to be heavy and therefore more difficult to support especially in end mounted installations. The Lithonia QUANTUM combo could be rapidly and easily mounted at the top, back or ends with adequate support of the assembly being possible even when end mounted. Manufacture and maintenance of the Lithonia combo were facilitated by the virtual all-plastic structure of the Lithonia product which allows at least portions of the product to be positively and readily snap-fitted to each other. While the QUANTUM combo evidenced significant advantages in this art, the combination of two essentially different and distinct forms of emergency lighting into a single product with both the exit sign and the emergency lighting unit retaining its own housing inter alia such as would be employed in their separate use has caused combo products to continue being somewhat bulky in size and to be less attractive than most other forms of emergency lighting have become in recent years as the industry has devoted increased attention to the appearance of emergency lighting products generally.
Accordingly, the art has experienced a long-felt and continuing need for improvement of a combination exit sign and emergency lighting unit or combo product to the end that such products become a true integration of an exit sign and an emergency lighting unit capable of supporting the weights of batteries necessary for providing power to both sides of an exit sign as well as unit lamps including remote unit lamps. In addition to the need to support greater battery weights than previously necessary in exit signs alone, the need exists in a combo to support greater weight than is normally experienced with an exit sign per se so that a combo can be safely and positively mounted in wall or ceiling installations. The art has thus felt the need for the present combo invention which integrates the functions of an exit sign and an emergency lighting unit into a single housing with repositionable lamping elements mounted to exterior portions of the housing. The structure of the present exit/unit combo allows support of battery loads in tension rather than through the usual cantilevered support of loads disposed internally of a sign housing. The structure of the present combo housing provides support of such efficiency as to prevent warping or bowing of the housing over time, thereby providing substantially improved product quality along with substantially improved product appearance. The exit/unit combo of the invention is provided with significant structural features useful not only with the combo but also with exit signs per se and with emergency lighting units per se as well as remote emergency lighting units., The present invention thus provides substantial improvement over the prior art by the provision of an integral and integrated exit/unit combo characterized by ease of assembly, installation and maintenance as well as by extraordinarily acceptable appearance.
The invention provides an emergency lighting fixture which combines the functions of an illuminated sign, particularly an exit sign, with an emergency lighting unit, the structural combination being integrated into a single housing which internally contains those structural elements necessary to produce the functions of the feature and which carries emergency lamping externally of the housing at multiple locations thereby providing extraordinary flexibility in use. The present combination of an exit sign and an emergency lighting unit or xe2x80x9cexit/unit comboxe2x80x9d is preferably formed of a polymeric material such as polycarbonate/ABS, thereby allowing molding of a fixture housing with most of the structural elements necessary to produce the functions of the fixture being integrally formed with the housing, these molded structural elements and other structure contained within the housing being located in the housing in a manner whereby the elements combine to produce synergistic effects in addition to the primary functions of the structural elements, the fixture being totally integrated as to structure and function as well as being substantially integral in construction. Formation of the fixture essentially from moldable material further allows integral formation of snap-fitting structural elements which not only provide easy snap fitting of facing plates to the housing to form the primary structural portion of the combo per se but also the integral formation of snap-fitting structure with bulb holders, battery mounting elements and option board storage elements inter alia. Assembly of the fixture is therefore facilitated at least in part due to the reduced number of individual parts occasioned by the integral nature of the housing inter alia.
The housing of the present exit/unit combo fixture is configured to support battery weights inter alia which are typically greater than those battery weights encountered in conventional exit signs due to the need to operate exit lighting, unit lighting and even remote unit lighting with a single battery disposed within the housing. In order to accommodate greater battery weight and the weight of the fixture itself, the battery is centered with the housing disposed at a lower portion thereof, battery location couples with a central, vertical structural beam known as a xe2x80x9cladderxe2x80x9d allows support of the battery inter alia in tension rather than in a cantilevered arrangement as has been previously employed in exit signs and the like. The structural features such as the ladder integrated with location of major weighting such as the weight of the battery actually allows use of a material such as plastic for formation of the fixture, the self-support provided by the structure itself preventing warping and bowing of the plastic exit/unit combo fixture over time such as would occur with a fixture having the weight of the exit/unit combo fixture if not provided with the integrated structural relationships of the invention. The dimensional stability of the present exit/unit combo fixture occurs due to the structural features of the fixture which maintain substantial portions of the fixture weight in tension.
The exit/unit combo fixture of the invention provides xe2x80x9cunitxe2x80x9d emergency lighting by the disposition of one or more emergency lamps mountable at different locations on the periphery of the fixture housing to accommodate differing lighting situations. The lamps are mounted by lamp holders fitted with swiveling concentric spherical structural elements which allow movement of the lamps with a degree of freedom not previously possible, the structure of the concentric spherical elements additionally yielding a compact profile which is not only attractive in appearance but functional due to the volumetric efficiency thus provided. The lamp holders of the invention are formed with torsion snap elements which fit into slots formed in peripheral edges of the housing, the slots receiving the snap elements of the lamp holders to positively mount the lamp holders in desired locations on the fixture. The particular snap element/slot arrangement of the invention allows rapid and ready mounting and dismounting of the lamp holders to and from the fixture housing with positive locking of the lamp holders to the housing once assembled. The lamp holders of the invention can be removed from the present fixture and mounted to remote slave mounting stations driven by the fixture with the snap elements of the lamp holder fitting into arranged slots of the slave station. Further, the lamp holder can be mounted to a station separate from the fixture with battery or other operation, the lamp holder being mounted to the station through use of the snap elements of the lamp holder in cooperation with slots formed in the station.
Various other features of the invention include structure for minimizing the xe2x80x9cshadowxe2x80x9d of the battery appearing through face plates of the exit/unit combo fixture; registration structure for mounting of a diffusion panel in a face plate of the fixtures; routing of wiring in association with the ladder support and in front of the battery with the use of slack in the wiring and structure for compartmentalization of electrical components within the interior of the fixture housing including snap-mounting of a capacitor inter alia. Many of the inventive features disclosed herein are useful in fixtures other than exit/unit combo fixtures and are disclosed for use in that variety of fixtures for which these features find utility. Use of these features is thus not limited to use in an exit/unit combo fixture.
Accordingly, it is an object of the invention to provide an integral exit/unit combo fixture having the capabilities of an exit sign and of an emergency lighting unit integrated into a fixture formed with a single housing for containing a substantial portion of the structures and for mounting emergency unit lamps on the housing externally thereof and at repositionally distinct locations of the housing.
It is another object of the invention to provide an integral exit/unit combo fixture substantially moldable of a polymeric material to allow formation of substantial structural portions of the fixture with a fixture housing, the housing and associated face plates being rapidly fitted together with snap features, components of the fixture internally of the housing being snap-fitted to the housing for rapid assembly thereof, structure holding emergency lighting lamping further being rapidly snap-fitted to the housing at predetermined locations on the exterior of the housing.
It is a further object of the invention to provide an integral exit/unit combo fixture substantially moldable of a polymeric material with structural support features providing dimensional stability to the fixture thereby minimizing warping and bowing of the fixture over time in spite of substantial weight occasioned by the use of heavy batteries as well as the weight of the fixture itself, the fixture including internal support elements which mount battery weight as well as the weight of the fixture per se substantially in tension.
It is a still further object of the invention to provide an integral exit/unit combo fixture having unit lighting provided by lamps mounted on exterior portions of the fixture by lamp holders mounted to the fixture by tension snap elements, each lamp being mounted by a swiveling double concentric structure which allows an extraordinary range of movement of the lamp and which allows formation of the unit lighting structure with a compact profile, the fixture requiring a reduced volume and vertical height for mounting of the fixture, the fixture being also mountable with the back of the fixture directly against a flat surface such as a wall.
Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments.